This study will test the efficacy of Acupuncture/Moxibustion (Acu/Moxa) to improve the symptoms associated with Irritable Bowel Syndrome (IBS). IBS has been defined as abdominal pain/discomfort in the mid or lower gastrointestinal (Gl) tract, associated with defecation or a change in bowel patterns with features of disordered defecation. IBS affects 15 percent to 20 percent of North Americans. Current therapies: dietary modification, psychotherapy and drug therapies, are still under investigation, none are curative and some have significant side effects. The traditional Chinese medicine (TCM) approach of acu/moxa developed over centuries in Asia offers a subtle, holistic approach to symptom management for IBS. Acupuncture (including moxibustion) has been widely used for the treatment of various Gl disorders. However, few IBS acupuncture studies have the necessary rigor to evaluate this treatment. The proposed study is a randomized, blinded, sham/placebo controlled clinical trial of Acu/Moxa to reduce abdominal pain/discomfort and IBS secondary supporting symptoms (IBS-SecS) (intestinal gas, bloating, stool consistency). 171 adults, diagnosed with IBS-diarrhea (IBS-D) according to ROME Ill criteria, will be randomized to one of three conditions: 1: Protocol-oriented Acu/Moxa (standard); 2: Patient-oriented Acu/Moxa (based on individualized TCM diagnosis and point prescription) and 3: Sham acupuncture/ Placebo moxibustion (control group). All subjects will attend a screening/intake session followed by two treatment sessions per week for 4 weeks, one treatment session per week for 4 weeks, and 2 long-term non-treatment follow-up sessions at weeks 12 and 24. All subjects will be assessed by a Diagnostic Acupuncturist (blinded to treatment assignments), receive interventions appropriate to their condition assignments (by licensed acupuncturists trained in TCM), and complete the same instruments and daily symptom diaries for the duration of the study. The primary intent-to-treat comparison of treatment group differences in abdominal pain/discomfort and IBS- SecS will use linear mixed model analysis with fixed effects of treatment, time, time-by-treatment and random effects of subject and error, and an AR(1) covariance structure. Continuous and categorical confounder influence on estimates of treatment effect will be explored in follow-up efficacy analyses. Secondary aims for treatment group differences in patient-rated overall symptom improvement, quality of life, psychological stress, healthcare utilization and work productivity will be similarly analyzed. Regression methods will identify how changes in IBS symptom severity are differentially associated with functional health outcomes, and will explore which TCM diagnoses should be targeted by practitioners treating IBS patients. Based on the analytic objectives and analyses of our pilot results, this sham/placebo controlled, blinded, randomized study of diarrhea subtype patients, requires 57 subjects for each of three treatment groups (N=171). This provides 80 percent power at a 5 percent Type I error rate and incorporates in the calculation 15 percent attrition and a 30 percent placebo effect. PUBLIC HEALTH RELEVANCE: Irritable Bowel Syndrome (IBS) affects 15 percent to 20 percent of North Americans. Annual U.S. healthcare costs for the evaluation and treatment of lBS exceeds 20 billion dollars. This application will test a symptom management strategy to improve lBS symptoms (abdominal pain, gas, bloating and altered stool consistency). The methodology employed seeks to evaluate a Protocol-oriented (standard) vs. a Patient-oriented (individualized) protocol using traditional Chinese medicine practices in a RCT.